I have been pondering this for a while. Situation is; I am in the process of an engine and trans swap. Ran into many delays and problems due to past mechanics doing things to make my life difficult. My engine is rebuilt and I am almost finished modifying the rest of the car for the swap (fuel system, A9P swap, and a lot of electrical work), but I have no time to search out a trans rebuilder. A few years ago, I could easily find people that did this work, but now, I can't find anybody within 200 miles of me. So the questions are: can I baby the stock AOD with a stall converter until I get a rebuilt trans? The nuts holding the stock converter are seized to the flexplate and I have no idea how to get them off without breaking things. Figured I would get the stall converter that I would get for the hi-po trans and run that; then swap transmissions when the time comes. Is this feasible?

So, I am attempting to install my AOD onto the back of my engine and have run across a snag. My new torque converter measured out to 11.5" and slid onto the flexplate smoothly, but the holes on the flexplate are shifted a little so that a couple of the torque converter studs are up against the sidewall. There is no play with the torque converter despite getting the "3 clunks" and having 1/4" clearance between the tip of the studs and bell housing flange. I have had people tell me to bore the stud holes in the torque converter out 1/16" and again, my Dad and his machinist buddies are telling me not to do that. Not sure what to do. I feel that I shouldn't have it tight like that, but I am a little squeamish with boring/reaming holes on things that need to be centered.

I got a flex plate from the same manufacturer as the torque converter with the same results

Am I doing something wrong? Is this a common problem? I am giving serious consideration in sending both TC and flex plate back and ask the manufacturer to exchange with units that have been test fitted properly.

I know I can wiggle the TC when I am installing it. Didn't think about it settling downward after it is installed. I know that when I test fitted them dry (before installing the flex plate and TC) the holes were still shifted. The only measurements I took were the bolt spacing on both the flex plate and TC; the bellhousing flange to tip of the stud (7/16"); and the back of the flexplate to the cover plate on the back of the engine (3/4").

So I figured out the issue; well, I was told by the manufacturer what the issue is. Most flexplates aren't specifically made for the TC of an AOD trans; they are made to fit a C4; which is a tenth of an inch off. I had to ream the mounting holes out to 29/64" to get it to fit, dry. When I mounted the engine and trans together, it still gave me trouble. So I separated the engine and trans and rotated the engine and remounted a few times until it lined up on the 3rd try. Then I got my end play. This may be atypical for this engine/trans combo; but this is what I had to do.

Now I have to deal with installing the small block and trans into a full-sized car. Getting the old engine and trans out was easy; putting them back in is another story altogether.